Mandrel-seating apparatus for tube-bending machines



' I. LEEZENBAUM.' A MANDREL SEATING APPARATUS FOR TUBE BENDING MACHINES.

APPLICATION FILED SEPT-9.1920- 1304397.

Patented J an. 24, 1922.

INVENTOR UNITED STATES PATENT OFFICE.

ISADORE LEEZENBAUM, OF NEWARK, NEW JERSEY, ASSIGNOR TO GENERAL TUBE COMPANY, OF NEWARK, NEW JERSEY.

MANDBEL-SEATING AIPIARATUS FOR TUBE-BENDING MACHINES.

Specification of Letters Patent.

Patented Jan. 24, 1922.

Application filedSeptember 9, 1920. Serial No. 409,228.

To all whom it may concern:

Be it known that I, ISADORE LEEZENBAUM, a citizen of the United States, and a resident of Newark, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Mandrel-Seating Apparatus for Tube-Bending Machines, of which the following is a specification. This invention relates to an apparatus which is to be used in conjunction with a tube bending machine so that the mandrel usually employed inside a tube that is being bent can be seated at the proper place within the tube to insure a smooth, unwrinkled bending of the tube, which seating by hand is in many cases difficult and unsatisfactory, and in some forms of tubes well nigh impossible.

The invention is further designed to provide an apparatus which is easily operated, as the mandrel is seated and withdrawn by power.

Another object of the invention is to pro-- vide an apparatus of this kind in which the rod on which the mandrel is carried is supported near its front end and is projected with a limit, so that the mandrel is always moved forward to the same place relative to the bending or forming roll, whether the bent portion of the tube is short or long, and the apparatus can also be used in conjunction with a stop plate which acts as a gage and against which the tube to be bent abuts when in position to be bent.

The invention further consists in details of construction to be further enumerated hereinafter and finally embodied in the claims.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a perspective view of the apparatus, showing part of a tube bending machine. Figure 2 is a side view of a part of the apparatus, part of which is broken away to more clearly illustrate the construction and the operation of the device, and Figure 3 is a section on line 33 in Figure 2.

The invention is shown in conjunction with a tube bending machine 10 having the bending or forming roll 11 supported on the plate or table portion 12, the details of the tube bending machine not being set forth in this specification since they form no part of the present invention and they are well known to the trade. A tube 13 is shown in position to be bent.

The apparatus consists of a frame, which is preferably a long, narrow frame, and in the form shown it consists of a built-up girder formed of two girders 1 1 and 15 which, when assembled, form a frame that in cross-section is substantially I-shaped, the beams or girders being preferably spaced apart to make a solid construction and for purposes to be fully described hereinafter.

On the forward end of the frame is a stop plate 16, against which the tube 13 is adapted to abut, the plate 16 being perforated so that the mandrel 17 can pass through it into the tube 13, the mandrel 17. being mounted on a mandrel rod 18, the forward end of which is slidable in a yoke 19, which yoke is adjustable, as by means of the bolts 20, so that it can be moved back and forth on the frame, this adjustability permitting the withdrawal of the mandrel only a short distance in case of short work, or a longer distance in case of long work, at the same time having the support disposed as near as possible to the forward end of the rod.

The rod is propelled, that is, reciprocated, by a saddle 21, which is secured to the girder so that it slides thereon and is adjustable relative to the rod 18, one form of such adjustment consisting of the lock nuts 22 and 23, which are screwed onto the screwthreaded part 24: of the mandrel rod 18, this adjustment permitting the mandrel to be propelled forward when desired, the movement of the mandrel rod being limited by a fixed stop 25, so that the mandrel is sure to be forced forward to the same working point, whether bending long or short pipes or tubes.

The stop 25 is therefore rigidly secured to the frame. For moving the saddle 21 the construction illustrated provides for a rack 26, which is preferably mounted between the beams 14 and 15, which are spaced apart by the spacing blocks 27, which also act to support the ends of the rack 26, the rack 26 being in mesh with a pinion 28 on a shaft 29, which shaft extends transversely from the frame and is driven by the pulleys 30 and 31, one pulley running in one direction and the other pulley running in the other direction, the direction of the shaft being controlled by the clutch 32 operated by the 7 is adjusted relative to the yoke 21 by the nuts 22 and 23, the stop plate 16 is adjusted so as to assist in placing the pipe or tube to be bent in its proper position, and then by the operation of the lever the workmanoperating the machine can quickly and properly seat the mandrel inside the tube 13, and when the bending is finished it can be easily and quickly withdrawn to permit the insertion of another tube for the purpose of bending it.

in tube bending operations and is easily operated.

V I claim:

1 A mandrel seating apparatus fortube bend ng machines comprising a stop plate for the passage of a mandrel and as an abutment for atube, a mandrel rod with a manfor the passage of a man'drel,.a mandrel rod with a mandrel thereon, an adjustable yoke, 40 a fixed stop, a movable saddle, means for ad ustably securing the rod to the saddle, a rack -to whlch the saddle is secured, a plnion for actuating the rack, and reversible power mechanism for operating the pinion.

the pinion, a saddle on the frame and secured to the rack, a mandrel rod adjustably securedto the saddle, a mandrel on the forward end of the rod, a stop for limiting. the forward movement of the saddle, and

a yoke for supporting the forward end of the mandrel rod. 7 This apparatus saves a great deal of time 5. A mandrel seating apparatus for tube bendmgmachmes comprising a long narrow :trame consist ng of opposed channel beams spaced apart'tra nsversely, a rack mounted in the space, a pinionin mesh with the rack, means for reversibly rotating the pinion,'a saddle slidably arranged on the top of the j frame and secured to the rack, a mandrel rod adjustable longitudinally in the saddle,

a mandrel on the forward end of the mandrel rod, a stop to limitthe forward movement of the saddle,' and a stop plate having a perforation for the passage, of the mandrel and disposed so that the end of a tube to be bent can be placed so that its end abuts against the stop plate.

In testimony that I claim the foregoing, I have hereto set my hand, this llthday of February, 1920.

I. LEEZENBAUM. 

